%I #8 Mar 30 2012 17:40:21

%S 1,12,25,54,113,226,453,910,1821,3644,7303,14610,29231,58462,116939,

%T 233892,467803,935616,1871237,3742486,7484979,14969998,29939999,

%U 59880012,119760031,239520072,479040191,958080388,1916160779,3832321566

%N a(n)=a(n-1)+ p, where p is the least prime whose first digit equals the first digit of a(n-1) and p>=a(n-1)

%e a(0)=1, least prime >=1 with the first digit 1 is 11, so a(1)=1+11=12, least prime >=12 with the first digit 1 is 13, so a(2)=12+13=25, least prime >=25 with the first digit 2 is 29, so a(3)=25+29=54, ...etc.

%p A000030 := proc(n) op(-1,convert(n,base,10)) ; end proc:

%p A175523 := proc(n) option remember; if n = 1 then 1; else a1 := procname(n-1) ; fda := A000030(a1) ; p := nextprime(a1-1) ; while true do if A000030(p) = fda then return p+a1 ; end if; p := nextprime(p) ; end do: end if; end proc:

%p seq(A175523(n),n=1..30); # _R. J. Mathar_, Dec 05 2010

%Y Cf.A000040

%K nonn,base,easy,less

%O 1,2

%A _Ctibor O. Zizka_, Dec 03 2010